An itsy-bitsy mollusk in Borneo is the new record holder for the world's smallest known snail, a new study finds.

Its shiny, translucent, white shell has an average height of 0.027 inches (0.7 millimeters), breaking the previously held record by about a tenth of a millimeter. The former champion - the Chinese snail Angustopila dominikae -is the world's second-smallest snail, with an average shell height of 0.033 inches (0.86 mm), the researchers said.

Dutch and Malaysian researchers named the newfound snail Acmella nana; its species name (nana) is a reference to the Latin nanus, or "dwarf." Acmella nana is so small that the researchers couldn't see it in the wild without a microscope. [Amazing Mollusks: Images of Strange & Slimy Snails]

But the researchers knew exactly where to hunt for unknown mollusks: Snails tend to live on Borneo's limestone hills, likely because their shells are made of calcium carbonate, the main component of limestone, said study co-researcher Menno Schilthuizen, a professor of evolution at Leiden University in the Netherlands.

"When we go to a limestone hill, we just bring some strong plastic bags, and we collect a lot of soil and litter and dirt from underneath the limestone cliffs," Schilthuizen told Live Science.

They sieve the contents, and dump the larger objects (including the snail shells) into a bucket of water. "We stir it around a lot so that the sand and clay sinks to the bottom, but the shells- which contain a bubble of air - float," Schilthuizen said.

Then, they scoop out the floating shells and sort them under a microscope.

"You can sometimes get thousands or tens of thousands of shells from a few liters of soil, including these very tiny ones," he said.

It's unclear what Acmella nana eats, because the researchers have never seen it alive in the wild. But the researchers have observed a related snail species from Borneo, Acmella polita, foraging on thin films of bacteria and fungi that grow on wet limestone surfaces in caves.

The newly identified snail, the world's smallest on record, is tiny compared to the small font used in the journal ZooKeys where it is described. |
Menno Schilthuizen/Naturalis Biodiversity Center

"Probably, Acmella nana lives in a similar way," Schilthuizen said.

The new tiny record holder lives in at least three places in Malaysian Borneo. (The island of Borneo is divided among three countries: Malaysia, Brunei and Indonesia.) So, it's unlikely that it will be wiped out if one of its environments is destroyed. However, other snail species are not so lucky, Schilthuizen said.

There is a lot of calcium carbonate in the tropics (in fact, the calcium carbonate there is made from ancient mollusk shells), but it erodes rapidly, leaving behind isolated peaks of limestone, Schilthuizen said. As species are secluded on limestone peaks, they evolve into new species.

Borneo boasts a high diversity of snails - possibly up to 500 species - but these native creatures can be wiped out if developers or other disturbances destroy a limestone habitat, Schilthuizen said.

For instance, "A blazing forest fire at Loloposon Cave could wipe out the entire population of Diplommatina tylocheilos," Schilthuizen said in a statement, referring to a snail whose sole habitat lies in that cave.

Many of these limestone hills are being quarried for cement, and Schilthuizen and his colleagues have already documented native snail species that have gone extinct after their entire habitats were destroyed. Perhaps, he said, these companies could quarry just part of a hill and leave the other part untouched to promote the continuation of these species.

Imagine you have to carry a shell on your back and that you're driven to eat the right foods to nourish that shell, and that some consider you a pest while others consider you food. Now take into account that you're so slow that anything that wants to eat you probably can -- you're not a fleet-footed evader of predators.
Welcome to the life of a snail. You'll never find 100% agreement that they're cute, but there's no denying that their grim determination makes them at least a bit noble. (OK, that might be a bridge too far, but you get the idea!) Herein we take a look at some of these slow-moving critters.
Of course, the shell is a snail's biggest show-stopper. They'll vary widely in color by species and are usually made of calcium carbonate, forming a spiral shape.
To make a shell, snails use a bit of their own hardware called a mantle -- a thin, skin-like organ that secretes a liquid made up of shell material. The liquid hardens and forms the shell. Over time, the mantle releases yet more liquid, adding to the size of the shell.

Snails can be nearly invisible to the naked eye or reach more than 1 foot long. They're found in fresh water, salt water, and on land.
They get knocked for their, well, snail-like pace, but it's not like snails can't move at all. Locomotion for most snails is by means of a large flat foot -- more like a body-length muscle -- underneath them that helps them glide across layers of mucus they secrete to smooth their way forward. It will even leave some slime in its wake, if you watch closely for it.
You might be wondering

how

slow they are. Given it's football season, we'll use 100 yards as a metric. If a garden snail were to receive a kickoff in its end zone and return it all the way for a touchdown, you would have to wait about two hours to see it reach the other end and spike the ball. And garden snails are the absolute speedsters of the snail world!

Land snails will typically eat fruit, dead plants, some live plants, and even bark. Freshwater snails will feast on algae, dead marine life remains and plants, while sea snails enjoy algae as their main course.
Snails have rows of small teeth that sit in long, tongue-like organs called radulas. They don't chew their food so much as grind and tear it with these teeth.

Of course, food in the animal kingdom is often a two-way street: You're either eating or being eaten. A snail has plenty of things that would like to eat it, so that's where its shell comes in. If a predator like a snake or a bird is nearby, a snail can crawl in its shell and seal it off. It can stay holed up like that for days to weeks if it wants to.

Remember the mantle, the snail's organ that secretes material for the shell? Land snails breathe using a lung set into it.
Sea snails, meanwhile, breathe through gills. Like fish, they use them to get oxygen from the water. Freshwater snails sometimes have gills, too, while others have lungs. When the latter need to breathe air, they surface and take a gulp.

Land snail eggs are not much bigger than a letter on your computer screen. Over a couple of days, a land snail will lay up to 100 eggs, burying them in shallow holes covered with dirt and their own slime. Most won't survive predation; those that do will hatch in 2-4 weeks.
Sea snails will deposit their eggs by the thousands on the ocean floor, though most won't fare any better than those on land. Freshwater snails may deposit their eggs above the water line, such as those of the apple snail, shown here.

Unfortunately for them, some species of snail, such as abalones and some land snails, are eaten by people. France, for example, raises them for that purpose. (Snail fans who don't see them as food will want to avert their eyes from escargot.)

Most snails are hermaphrodites, with both male and female reproductive organs. A mating ritual that can last several hours results in each snail having eggs to deliver, after they grow for a bit inside the snail. As we've seen, most young'ins won't make it, but a few will, and snails will find a way to keep on going.